Combined selective adsorptioncatalytic cracking process



April 17, 1951 s. F. PERRY COMBINED SELECTIVE ADSORPTION-CATALYTICcRAcxING PRocEss Filed Jan. a, 1949 Stephen. :Der'rg Unventor @g5/bull 1Cltbor'rze Patented Apr. 17,: 195i `COMBINED SELECTIVE ADSORPTION-CATALYTICv CRACKING PROCESS Stephen F. Perry, Roselle, N. J., assignorto Standard Oil Development Company, a corporation of DelawareApplication January 8, 1949K, Serial No. 69,911

l claims. (o1. 19e-52) The present invention is concerned with aimproved process for the refining of petroleum hydrocarbon fractions.The invention is more particularly concerned with the processing of ahydrocarbon fractionv utilizing an adsorption stage and catalyticcracking stage in combination one. with-the other. In accordance `withthe process of the present invention a petroleum fraction iscatalytically cracked using a solid catalyst. The catalyst is removedfrom the cracking zone and regenerated in a regeneration zone. At

.least a portion of the catalyst from the regeneration zone is thenpassed throughV an adsorption Azone wherein the regenerated catalystcontacts Aa petroleum fraction to remove therefrom the relatively morearomatic type constituents.

This portion of the catalyst containing the adsorption constituentshaving a relatively high carbon to hydrogen ratio is then passed to thecatalytic y cracking zone. A preferred embodiment of the present processis to contact a hydrocarbon fraction boiling in the lubricating oil orkerosene boiling ranges with a catalyst; to remove the catalyst and toutilize the same to crack a hydrocarbon Vfraction boiling in the gas oilboiling range.

. It is well known inthe art to rene petroleum oils by ditilling thecrude or feed stream in order to segregate various hydrocarbon fractionssuch as those boiling in the gas oil boiling range, the

kerosene boiling range and in the lubricating oil boiling range. Usuallythe practice is to crack the gas oil fraction by either a thermal or afluid "or fixed bed catalytic cracking operation. Temperatures andpressures, as well as feed rates may be varied depending upon theparticular stock being cracked. Cracking temperatures are generally inthe range from about 750-1000 F., while the pressures are in the rangefrom atmospheric to 1000 pounds. Preferred cracking temperatures are inthe range from about 850"2 F.9'75 F. If `a fluid operation is utilizedany suitable cracking .are undesirable with respect to the fractionsboil- 'ingin the kerosene range. pIt is, thus, desirable to remove thesearomatic fractions from certain Y products such as kerosene, andlubricating oils.

Vmeans of feed line l.

This is usually accomplished by various pro.- cedures such as anadsorption operation, an acid treating operation and the like. Whensolid adsorbents are utilized, it is necessary to regenerate theadsorbent usually by burning, solvent treating or an equivalent method.

In accordance with the present invention a combination processconsisting of a cracking and an adsorption stage is utilized. -Theinvention may be readily understood by the drawing illustratingembodiments of the same.

Referring to the drawing, a feed oilwhich'for the purpose ofillustration is taken to be a crude oil, is introduced into distillationzone l0 by Temperature and pressure conditions are adjusted indistillation zone I0 lto segregate; normally gaseous hydrocarbons,

which are removed from zone l by means of line 2, a fraction boiling inthe gasoline boiling range which is removed from zone l0 by means 'ofline 3, a gas oil fraction which is removed by means of line d, and alubricating oil fraction which is removed by means of line 5. A higherboiling fraction may be removed from zone I0 by means of line 6. It isto be understood that zone l l0 may comprise any suitable number and arllfraction is introduced into catalytic cracking zone 20 by means of line4. Regenerated or fresh catalyst is introduced into the top of catalyticcracking zone 2li by means of line 1, and the spent cata- :lystWithdrawn from the bottom of zone 20 by means of line 8. For the purposeof description it is assumed that the cracking catalyst comprises silicaand alumina. Temperature and pressure conditions in zone 20 as well asoil and catalyst feed rates are maintained within a range to secure thedesired cracking of the gas oil fraction and tov produce lower boilingconstituents. A product stream is withdrawn overhead from zone 2U bymeans of line 9 and introduced into distillation zone B. Uncondensedgases are removed overhead from zone 3B While a cracked gasoline 'iswithdrawn by means of line i I. Heavier higher boiling constituents areremoved from zone v3f) by means of line I2. It is to be understood thatsuitable cooling, condensing and heat exchange equipment is utilized.

The spent catalyst is withdrawn from zone 20 by means of line 8 ashereinbefore described and introduced into regeneration Zone 40. Thecatalyst is regenerated in zone I0 preferably by burning the catalystwith air which is introduced into zone 40 by means of line I3. Steam isalso utilized and is introduced by means of line I4. A portion of theregenerated catalyst is withdrawn from the bottom of zone 40 by meansVof line 'I and returned to Zone 20. present invention a portion of thiscatalyst is segregated by means of line I5, passed through a heatexchanger Zone, introduced to cyclone separator I8 and then passed tocontacting zone 50.

The lubricating oil fraction withdrawn from Zone I by means of line 5 ispreferably mixed with a diluent comprising liquied propane, butane or alight naphtha which is segregated in zone 30 and introduced into line 5by means of line I'I. The lubricating oil is introduced into contactingzones 50 and 60 alternately. In zone 50 and in zone 60 the lubricatingoil fraction contacts the regenerated adsorbent under conditions toremove the more aromatic type constituents, the sulfur compounds, resinsand gumforming materials selectively. Thus, the quality Vof thelubricating oil fraction is materially imheater I9 and introduced intodistillation Zone 10. Temperature and pressure conditions are adjustedin zone 'I0 to remove overhead by means of line 2i the diluent which maybe handled as desired but is preferably condensed and recycled tocontacting Zones and 60. The high viscosity lubricating oil fraction iswithdrawn from zone 'I0 by means of line 22 and may be further treatedas desired.

The adsorbent is withdrawn from filter 80 by rleans of line 23 and isintroduced into cracking zone 20 by means of line 1. If desired, thisstream may be subjected to a mild steaming or purging operation prior tointroducing the adsorbent into the reactor. This steaming or purgingoperation is conducted under conditions such that the loosely helddiluent is removed and the adsorbed aromatic fraction is retained.

The more aromatic type constituents which are retained on the spentadsorbent has very poor lubricant qualities but is an excellent feedstock for a cracking operation. The resulting gasoline has a relativelyhigh anti-knock value. Similarly, when employing the adsorbent step forkerosene refining, the aromatic kerosene fraction is retained by theadsorbent and recycled to the cracking step. Thus, the quality of thekerosene, as well as the quality of the resulting gasoline is improved.The present invention comprises a combination operation wherein aromaticconstituents are removed from a feed oil andv returned to a crackingZone under conditions so that both the quality of the heavier fractionand the quality In accordance with the 4 of the gasoline fraction ismaterially improved. The invention is specifically adapted to theproduction of high quality kerosenes, lubricating oil and gasolines.

The invention is generally concerned with the catalytic cracking ofhydrocarbon constituents boiling in the gas oil boiling range in thepresence of adsorbed aromatic type constituents removed from a petroleumfraction boiling either above or below the gas oil boiling range. It ispreferred that the aromatic constituents present be secured from aheavier boiling fraction, as for example, 'a fraction boiling in therange from about 675 F. to 900 F. A satisfactory operation is alsoattained when the aromatic constituents present in the catalyticcracking zone are segregated from kerosene fractions boiling in thegeneral range from about 375 F. to 550 F. In general it is preferredthat the gas oil fraction boil in the range from about 400 F. to 700 F.

The preferred catalyst comprises a silica-alumina catalyst particularly,a catalyst which comprises about -90% S102 and from 10-20% A1203. Aparticularly desirable catalyst comprises SiO2 and 15% A1203.

The amount of catalyst segregated from the regeneration zone and passedto the adsorption zone may vary considerably. However, in general it ispreferred that fromV about 20-50% of the catalyst withdrawn from theregeneration zone is passed through the adsorption zone.

The quantity of catalyst used in the adsorption zone when contacting apetroleum oil boiling in the lubricating oil boiling' range should varyin the r-ange from about' 2-6 parts by weight of catalyst per 1 part byWeight of oil. The volume of diluent used should be from 2-10 parts ofdiluent per part of oil. The Vtemperature employed in the adsorptionzone may be in the range from about 80 to 300 F., although it ispreferred that the temperature be in the general range from to 150 F.The time of Contact should be in the range from about 5 to 30 minutes,preferably from about 15 to 20 minutes. When the oil being contacted inthe adsorption zone boils in the kerosene boiling range the amount ofcatalyst used should be in the range from 0.5 to l part by weight ofcatalyst per 1 part by weight of oil. The amount of diluent used underthese conditions should be in the range of from 1 to 3 parts of diluentper p-art of oil. The temperatures used are similar to those used. whencontacting lubricating oils.

It is claimed:

1. Improved process forv the production of a high quality lubricatingoilY and a high quality cracked gasoline from a petroleum feed oil,which comprises segregating saidfpetroleum feed oil into a petroleumfraction boiling in the gas oil boiling range and into a petroleumfraction boiling in the lubricating oil boiling range, catalyticallycracking said fraction boiling in the gas oil boiling range in acracking zone with a cracking catalyst under conditions to produce acracked gasoline, separating the cracking catalyst and regenerating thesame, segregating a portion of said regenerated cracking catalyst andcontacting said petroleum fraction boiling. in the lubricating oilboiling range withY said catalyst under conditions to adsorb thereon themore aromatic type constituents, thereafter separating said catalystfrom the oil and recycling said cracking. catalyst containing saidadsorbed constituents to said cracking zone.

2. Process as dened by claim 1 wherein said gas oil boils in the rangefrom about 40G-700 F. and wherein said lubricating oil boils in therange from about 675 F. to 900 F.

3. Process as dened by claim 2 wherein said catalyst comprises fromabout iiD-90% S102 and 10-20% of A1203.

4. Improved process for the production of a lhigh quality lubricatingoil and a high quality cracked gasoline from a petroleum feed oil, whichcomprises segregating said petroleum feed oil into a petroleum fractionboiling in the gas oil boiling range and into a petroleum fractionboiling in the lubricating oil boiling range, catalytically crackingsaid fraction boiling in the gas oil boiling range in a cracking zonewith a cracking catalyst under conditions to produce a cracked gasoline,separating the cracking catalyst and regenerating the same, segregatinga portion of said regenerated cracking catalyst, adding a diluent tosaid petroleum fraction boiling in the lubricating oil boiling range,and contacting said petroleum fraction with said segregated portion ofregenerated catalyst under conditions to adsorb thereon the morearomatic type constituents, separating said catalyst from the oil andrecycling said catalyst to said cracking zone.

5. Process as dened in claim 4, wherein said catalyst recycled to saidcracking zone is treated with steam in a manner to remove the diluentand in a manner that said catalyst retain said adsorbed constituents.

STEPHEN F. PERRY.

REFERENCES CITED The following references are of record in the ille ofthis patent:

UNITED STATES PATENTS

1. IMPROVED PROCESS FOR THE PRODUCTION OF A HIGH QUALITY LUBRICATING OILAND A HIGH QUALITY CRACKED GASOLINE FROM A PETROLEUM FEED OIL, WHICHCOMPRISES SEGREGATING SAID PETROLEUM FEED OIL INTO A PETROLEUM FRACTIONBOILING IN THE GAS OIL BOILING RANGE AND INTO A PETROLEUM FRACTIONBOILING IN THE LUBRICATING OIL BOILING RANGE, CATALYTICALLY CRACKINGSAID FRACTION BOILING IN THE GAS OIL BOILING RANGE IN A CRACKING ZONEWITH A CRACKING CATALYST UNDER CONDITIONS TO PRODUCE A CRACKED GASOLINE,SEPARATING THE CRACKING CATALYST AND REGENERATING THE SAME, SEGREGATINGA PORTION OF SAID REGENERATED CRACKING CATALYST AND CONTACTING SAIDPETROLEUM FRACTION BOILING IN THE LUBRICATING OIL BOILING RANGE WITHSAID CATALYST UNDER CONDITIONS TO ADSORB THEREON THE MORE AROMATIC TYPECONSTITUENTS, THEREAFTER SEPARATING SAID CATALYST FROM THE OIL ANDRECYCLING SAID CRACKING CATALYST CONTAINING SAID ADSORBED CONSTITUENTSTO SAID CRACKING ZONE.